It’s been a long time since anyone tried landing on Venus, one of the most hostile environments in the Solar System. Covered in sulphuric acid clouds, the surface temperatures approach 460 C (860 F) with atmospheric pressure 90 times that of Earth. Lead, zinc and tin are liquids, and the weight of the carbon dioxide air is roughly equal to that found a kilometre under the ocean – enough to crush a submarine.
http://www.bbc.com/future/story/20160705-the-toughest-spaceship-weve-ever-built
